SEGMENT-EDITOR : Segment-Ranges

Not all motion-laws have a Segment-Range.

These parameters 'clip', or 'remove', the start or end of the mathematical-function that defines the motion-law.


Start and End Segment Ranges

Start and End Segment Ranges

 Segment Ranges  - only with, but not all, Traditional Motion-Laws.

The parameters are:

Start-Range
End-Range

The Segment Range values are limited to:

 0 Start Range < End Range ≤ 1


Notes:

Segment-Width does NOT change.
Position at the start and end of the segment do not NOT change.

SegmentRange-0-0

The images shows the acceleration graph of a Modified Sinusoid motion-law.

Start-Range = 0.0
End-Range = 1.0

The Segment-Width does not change.

SegmentRange-0210

Example 2

Start-Range = 0.2
End-Range = 1.0

A 'Start-Range' of 0.2 removes the first 20% of the Modified-Sinusoid segment.

The Segment-Width does not change.

SegmentRange-1008

Example 3

Start-Range = 0.0
End-Range = 0.8

An 'End-Range' of 0.8 removes the last 20% of the Modified-Sinusoid segment.

The Segment-Width does not change.

see also: Segment Editor: Segment-Width, Segment Editor: Parameters

Dwell-Rise-Dwell Asymmetrical Motion

Symmetrical Motions

The crossover [acceleration becomes deceleration, or vice-versa] is at the mid-point of the Segment-Width.

Asymmetrical Motions

The crossover is not at the mid-point of the Segment Width.

When to use Asymmetrical Motions

Often, you want a machine tool to accelerate quickly from a dwell until it reaches a peak velocity sooner than the 0.5 point, followed by deceleration that takes longer and more gradually than the standard deceleration.

Or vice-versa.

AsymmetricalModSine

You can model an asymmetrical motion with two segments that have the same motion law - for example a Modified Sinusoid.

 

Orange Line graph : Symmetrical Mod-Sine Motion-Law : λ = 0.5

This motion-law is usually specified with one standard Mod-Sine segment Here, we have specified it with two Mod-Sine segments.

Segment 1

Machine angle: 0 - 180º  [ 0 - 0.5 of total duration]

Displacement : 0 - 50 units

Segment Ranges = 0 and 0.5.

Segment 2

Machine angle: 180 - 360º [ 0.5 - 1.0 of total duration]

Displacement : 50- 100 units

Segment Ranges = 0.5 and 1.

 

Black Line graph : Asymmetrical Mod-Sine Motion-Law : λ = 0.25

Crossover @ 0.25 = 90º machine angle.

This can be modelled with two Mod-Sine motions:

Segment 1:

Machine angle: 0 - 90º [0 - 0.25 of total duration]

Displacement : 0 - 25 units

Segment Ranges : 0 and 0.5.

Segment 2:

Machine angle: 90 - 360º [0.75 - 1.0 of total duration]

Displacement : 75 - 100 units

Segment Ranges = 0.5 and 1.

Characteristics Values of Asymmetrical Motion-Law.

Velocity : No Change to Symmetrical Motion-Law.

Acceleration: Segment 1 :  Cas = Ca / 2λ ;

Acceleration: Segment 2 :  Cas = Ca / 2(1-λ)

Tutorial and Reference Help Files for MechDesigner and MotionDesigner 13.2 + © Machine, Mechanism, Motion and Cam Design Software by PSMotion Ltd